VoIP on Separate Interface

Filip

Hello.
I am not sure if I am posting under the right topic so feel free to move it if necessary.

I would like to have two LAN networks connected with to separate interfaces with the reason being that I need to have a router supplied by my ISP for my VoIP to function properly. For it to work I have to have that router connected by its WAN port, so my question is if and how I would create a separate LAN for that router with no firewall or security at so that nothing will be blocked and keep my other LAN with all the other computers connected and secure at the same time.

I have the hardware for a second LAN installed in my pfSense box already
I have asked for ports but the ISP’s support does not know them
The router with the VoIP functionality is a Zyxel with the model number: P-2812HNU-F1

I am doing it wrong and you have a suggestion on how I should do it instead, please tell me.

Thanks, Filip

chpalmer

Easily done but-

Have you tried just plugging the VOIP routers WAN directly into your LAN?

Who is your VOIP provider?

This really is a general question and not NAT related…

Filip

Thanks you for the fast response.

Yes I have tried that and it does not work. The firmware running on the router is from what I have seen custom fitted to the ISP and the settings are downloaded automatically from some server which it can not do if I plug it in that way.

My ISP and VoIP provider is Bredbandsbolaget. I live in Sweden.

If my question is in the wrong place, how do I move it?

chpalmer

Try this-

Go to your pfSense gui at - /system_advanced_firewall.php

Go to the bottom to the TFTP Proxy. Select "LAN" and then save. See if that works for you…

chpalmer

Once you make this change make sure to reboot the voip device and let it sit for up to a good half hour. They can sometimes take a while to request their config file.

Filip

I set TFTP to lan and will see if anything happens.

But i suppose I have to open one or a few ports to let calls through, right? Or will TFTP take care of that too?

chpalmer

pfSense rewrites the source port and TFTP transfers such as your VOIP device uses to get its config file do not like that.

Its hard to tell if your VOIP provider will require any rules or not. It depends on how they are set up.

With one provider I need rules, the other I do not. Ive actually quit the one that doesn't need rules and ported those numbers to the one that does.

No NAT rules however. You should not need inbound NAT to a VOIP ATA (client device) these days.

Filip

After trying what you suggested I found that the WAN LED on the router lit up orange instead of green as it does if I plug in straight into the wall.
Although it still functions and provides internet access to a computer I plugged into its LAN for testing. It did however not download any
configuration files or made any changes to the settings as it should have done according to my ISPs website during the time I had it plugged in.
It is possible that it tries to receive something but fails as the WAN light flashes rapidly in bursts when plugged in to the pfsense box even if nothing is connected to it.

It is possible it needs to be port forwarded. I did a port scan and found out that several ports were open by default in the router.
This was scanned from inside its own LAN and there were nothing open from the WAN side. This is also right after a reset.

21 filtered ftp
22 open ssh
23 filtered telnet
53 open domain
80 open http
443 filtered https
7676 open imqbrokerd
10000 open snet-sensor-mgmt
10001 open scp-config
49152 open

All open on tcp.

It might not be necessary but I did it just in case it would be important and overlooked later on.

johnpoz

if the provider of this box can not provide you with the ports it requires if behind a firewall I would question that for sure - maybe the 1st level guy were talking about just didn't know. Ask to talk to an engineer.

Your other option is to sniff on pfsense interface this box is connected to and see what it is trying to do.

Or other option put this box in front of pfsense for your voip stuff, and make pfsense behind its nat.. Just forward all ports on your zyxel to pfsense wan IP, or make pfsense wan IP the dmz host, etc. Or turn it into a bridge, where pfsense would get your public IP but voip would still be handled by the device.

Other option is enable UPnP on pfsense so it can forward the ports it needs on pfsense.

Filip

I will try to get the ports by either sniffing them or calling the support again. I have asked to talk to a next level person, but there are none available. At all, they say at least.
I once got a number from them to an in depended company that knew more but took extra money for me calling in.

Meanwhile, is it possible to create a "transparent" interface that forwards the wan address to trick VoIP modem that it is the first, while actually pfsense is the first line?
I would like to do it like that because configuring the zyxel to act like a bridge is slowing down my network speed by a fair amount. It is not, or at least mine is not very fast.

How the ISP wants me to plug it all in:
ISP – zyxel – pfsense – LAN
\ – Phone

How I would like it to be:
ISP – pfsense – LAN
\ – zyxel – Phone

I do not know if it would work but I imagine I would be able to open every port in that interface to not block anything and still be safe on my LAN.

Filip

And thanks to you for helping me as well.

Filip

I scanned my network traffic while calling in and out and saw a reference to port 5060.
I saw some protocols that were used:

TCP
SIP
RTP
TRCP
Syslog

I also saw, while looking at the packets that were sent first during calls out and found, a reference to an md5 hash (supposedly a password), so I will not be filling in the information manually for some time.
The traffic flowed to a remote host that I could not ping and from a host other that my own IP.

This was done by making another computer a bridge with sniffing tools running on it and the zyxel connected to the forwarded port from the bridge.

So plugged everything back and I tried to open some ports in pfsense and point them to the zyxel router, but with no luck. Nothing is getting through.

johnpoz

You do understand that pfsense can sniff traffic on any interface, there is a gui to do it under diag. If you need to sniff on multiple interfaces at the same time I find it easier to just ssh to pfsense a few times and run whatever tcpdump I want in each shell, etc.

Filip

Yes, I do know that. It is just so that the zyxel router does not function as it should when behind pfsense. No the phone instantly returns an error sound without even transmitting anything.

So I wonder how I would create an interface that just passes all data along with my external ip address that I can connect the zyxel to?
That is the only solution I can think of.

johnpoz

that would be a 1:1 nat, but you would need more than 1 public IP if you wanted to send any other inbound traffic to anything else.

Just put the zyxel in front of pfsense would be easier solution.

Filip

Okay. If that is the best and easiest way to do it except putting the zyxel in front of everything else, let’s pretend I now have two IP-addresses with one connected to the phone.
What would I do to transfer data coming from the phone address to its router and keep the other address to the other interface?

chpalmer

I would just try creating a second LAN interface first.

Id be very surprised if you had to port forward anything at all but instead you just need firewall rules to allow the traffic.

Do you have an available interface on your firewall that you can use?

chpalmer

Further my bet is a couple of WAN rules pointed at your device's LAN address would work as well but Ive started putting all my voip devices on a secondary interface as well just for ease and to be able to segregate traffic for statistical purposes.

Question- Do you have admin access to your Zytel device?

Filip

Yes, I have an excess interface and I turned it into a new LAN with the same configuration as my other one, created when I installed pfsense.
I works just fine for everything except my VoIP.

I have access to my zyxel router but it is limited. I cannot update the firmware and view the VoIP configuration. That is all managed my ISP.
But I might be able to get them to do some things for me in I am not able to. There might be more settings that I am not capable of changing that I am not aware of.

I also just phoned my ISP and asked about IP-addresses and they told me I am able to get up to 5 with my current subscription.

Filip

I want to make this interface a straight hole into the internet with no nat or firewall so that something from my end can get an external IP-address from my ISP and sent data through pfsense.
In other words I want it to act like a switch.

I am not a pro so I need some help from someone who that can tell me how this may be done.